Very few of us have an image of Edward IV, most of us have an image of Henry VIII - the difference is Holbein: Holbein in England at Tate Britain

Holbein is one of Britain's greatest portrait painters and the exhibition at Tate Britain brings out both his outstanding talent and the pains he took over his work. The preliminary drawings, the notes, the studies of the details of English life and costume he made are displayed, as well as the portraits. Holbein was good and knew he was good. His boast was:

I am Hans Holbein. It is easier to criticise me than to imitate me.

It was justified.

Holbein's are the first accurate portraits of English men and women that we have, as good as colour photographs and with the extra insights and skill of a great painter. We feel that we know what these Tudor courtiers, gentry, merchants and scholars looked like. Their costumes may be of the past but these are contemporary faces looking at us.

Imagine a series of portraits of modern academics dressed up in floppy PhD hats and technicolour hoods, their faces showing a mixture of false pride and real deceit, ready to parade at a colourful degree ceremony for the dazed parents - that is what Holbein's Tudor worthies look like. How Holbein would have done justice to these professors' faces, capturing the sly and furtive young, the arrogant and insolent in their high noon, the old and care-worn faces, as he did with the people of his own time. Holbein's people are modern and Holbein was a genius. It is today's dolled-up vice-chancellors who look anachronistic. Besides the modern artists commissioned to add to the lines of portraits of oily vice-chancellors that line the flaking walls of "university" corridors fail to capture the person in the way Holbein could and did.

Thanks to Holbein, with a little help from David Starkey, we do know Henry VIII, whose iconic portrait by Holbein in 1536 advertises the exhibition. It is a shame that the larger mural paintings of the monarch by Holbein have not survived, only copies such as Henry VIII, 1570-5? and as preparatory drawings.

Henry, square and splendid, with his clothes exaggerating the size of his shoulders and his codpiece, with his jewels and his dagger, was made to look every 2.54 centimetres a king, yet he is also a distinctive individuals.

Holbein was part of the king's boasting, for in him Henry had at his court one of the finest designers of work for goldsmiths as well as the finest portraitist. He could show off in his palaces some of the best Renaissance craftsmanship of all kinds and this too is shown to us in the exhibition.

The most enjoyable portraits by Holbein are those of the grasping ambitious men around the king - courtiers, lawyers, politicians and worst of all, the humanists, those spin doctors learned in the classics. Virtuous men all look alike but the ambitious have individual characters that show in their faces. In scenes of Heaven and Hell the blessed all look upwards and bellow Cwm Rhondda in unison for all eternity in a single choir, but Hell is divided into circles, each with its own array of real faces. Saints all look the same because there are particular conventional ways of depicting sanctity but this is Tudor England and these are men on the make seeking immortality through this-worldly paint.

Look at Thomas and John Godsalve, 1528, the father rich, legal and ambitious for his son. They stand shrewd and hard faced behind a desk with pen and inkwell, the father and son looking forward to the son's success as Sir John Godsalve, 1532-3, courtier, still shrewd of face but now also wary almost apprehensive. Here too are Richard Cheseman, 1533 with his hooded falcon and direct eyes and Sir Henry Guildford, 1527 oozing with power, success and confidence like an Italian Renaissance prince or pope.

Each is a distinctive individual whose face and character you would remember. It is possession that gives men their individuality. "I own therefore I am". These men were the first English generation fully to understand this and Holbein the first accurately to record it. We can see the same quality earlier in a drawing by Holbein's father, Hans Holbein the elder, of Jakob Fugger, 1509, known as Jakob the rich Fugger. As every Egyptian schoolboy knows, the Fuggers were the greatest banking house in Europe, based in Augsburg, where Holbein was born. Taken together the complete Fuggers were worth more than most royal families. It shows in Jakob's face, simply and subtly drawn by Holbein's father. We are all born alike; it is ownership that shapes our ends.

The former is almost a portrayal of a medieval fraternity kneeling before an image of a saint (here played by Saint Henry VIII). The members of the Company of the Barbers and the Guild of Surgeons, united by Act of Parliament in 1640 to form a single set of bleeders, kneel as if in worship looking up at an oversized, crowned and throned, Henry VIII. They all look much the same and are identified by names written on their sleeves; they are a collectivity and it doesn't matter that the picture was a Holbein workshop job or that the heads have had to be restored. They are any old bunch of barber-surgeons, all gazing piously at the King as he hands them their new charter, their licence to kill.

Dr John Chambers, the King's physician, a founder of the Royal College of Physicians and not a member of the bleeding company, kneels at the King's left on the opposite side, set apart from the rabble of ill-educated sawbones, even today known as mere "Misters". Yet he does not stand out as an individual. To know him you have to look at Dr John Chambers 1571-2, an individual portrait made from the image taken for the group portrait. In a sense he ought to look just the same - but he doesn't. He now looks forward confidently from a face grim with age and satisfied ambition and not upwards deferentially at the King, like one of the mere mass of lancet wielders. His hands are no longer hidden but firmly gripping a pair of gloves as if they were the neck of a bag of fees. He is an individual who has achieved what he has and wants you to know it. Holbein could do that for him. Holbein lets us know.

By contrast Holbein's full frontal portraits of the Hanseatic merchants with their deliberate sense of Lutheran moralism are far less interesting. These men came to London from such great German trading cities as Gdansk, Wroclaw and Kaliningrad. They wanted paintings that emphasised memory and piety. They got them.

Holbein's best portraits are wonderfully real, some quite still, some poised to move. You have the illusion that the person is there in front of you. You feel like reaching out to touch Christina of Denmark, Duchess of Milan, 1538.

It is a full length portrait of a sixteen year old widow being considered as a bride for Henry VIII, at a time when women, indeed young girls, were pawns in games of landed property and citizenship, much as in Muslim Britain today. Just as men are what they own, so women in these worlds are what they can attract. Christina does. Sweet sixteen, her exquisite pale face and rich lips are framed by a black widows cap that conceals her hair and ears and by her long garment of mourning. Holbein has placed her as if in a corner, about to advance seductively towards the king. Poor Henry, not to have added this peach to his collection of wedded fruit.

Go and see Holbein in England and be entranced. And think of British Land, the biggest owner of commercial property in our country, who have sponsored the exhibition as they do much of the art that enriches our urban landscapes. Who owns adorns.